mcp-configuration

mcp-configuration is a cursor rule for Cursor from ekakit/lightfast-mcp. It costs 11 tokens per session (2,054 once invoked), scanned A, original, MIT.

A set of rules for working with MCP configuration files. MCP, or Model Context Protocol, is a standard for connecting AI agents to external tools and servers.

In plain words
What is it for?
Adding or updating MCP servers, troubleshooting their configuration, and following the documented Lightfast MCP setup patterns.
Why use it?
It tells the agent which configuration files to check and when to consult the upstream Lightfast MCP repository for current examples and fixes.

Cursor rule for Cursor

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add rules/ekakit/lightfast-mcp/mcp-configuration
Clone the repo
git clone --depth 1 https://github.com/ekakit/lightfast-mcp

Made for: Cursor.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for mcp-configuration

README.md
[![agentmods](https://agentmods.dev/badge/rules/ekakit/lightfast-mcp/mcp-configuration.svg)](https://agentmods.dev/rules/ekakit/lightfast-mcp/mcp-configuration)
Your own site
<a href="https://agentmods.dev/rules/ekakit/lightfast-mcp/mcp-configuration"><img src="https://agentmods.dev/badge/rules/ekakit/lightfast-mcp/mcp-configuration.svg" alt="Measured on agentmods" height="20"></a>
Per session 11 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 2,054 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00011 $0.02054
Opus 5 $0.00005 $0.01027
Sonnet 5 $0.00002 $0.00411
Haiku 4.5 $0.00001 $0.00205

Measured 4d ago against content hash cf58b0e4dbfc, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

mcp-configuration scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 4d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.cursor/rules/mcp-configuration.mdc · 252 lines

How it starts

The opening of the file, as written. The whole thing — 252 lines — stays where its author put it; the contents beside it link to each section on GitHub.

MCP Configuration Management

Overview

This rule applies when working with MCP (Model Context Protocol) configuration files, particularly .cursor/mcp.json and related server configuration.

File Patterns

  • .cursor/mcp.json
  • .cursor/mcp_*.json
  • config/servers.yaml
  • Files containing MCP server configurations

Upstream Repository Reference

Always reference the upstream repository for latest patterns and configurations:

  • Repository: lightfastai/lightfast-mcp
  • URL: https://github.com/lightfastai/lightfast-mcp
  • Documentation: https://mcp.lightfast.ai
  • Key Configuration Files:
    • .cursor/mcp.json: Local development MCP configuration
    • .cursor/mcp_global_example.json: Global Cursor configuration template
    • config/servers.yaml: Server orchestration configuration
    • pyproject.toml: Entry points and package structure

When to Fetch from Upstream

Always check the upstream repository when:

  • Adding new MCP server configurations
  • Updating existing server configurations
  • Implementing new server types
  • Troubleshooting configuration issues
  • Looking for configuration best practices
  • Understanding the latest server architecture patterns

Current Development Status

The upstream repository actively tracks development through GitHub Issues and Pull Requests:

🔄 Active Development Areas
  • New Creative Applications: Issues for Photoshop (#1), OpenSCAD (#2), Maya (#28), Cinema 4D (#27)
  • Feature Enhancements: OBJ import/export for Blender (#29), ongoing improvements
  • Infrastructure: Dependency management via Renovate (#4), CI/CD optimizations
📋 Issue Categories
  • Feature Requests: New MCP server implementations for creative applications
  • Enhancement: Improvements to existing servers and functionality
  • Dependencies: Automated dependency updates via Renovate bot
  • Documentation: Roadmap and creative applications documentation
🔗 PR Workflow Patterns
  • Feature Branches: Named as jeevanpillay/{feature-name} or feat/{application}
  • Automated PRs: Renovate bot handles dependency updates
  • Draft PRs: Used for work-in-progress features (e.g., Photoshop MCP #3)
  • Auto-generated Release Notes: CodeRabbit AI provides comprehensive PR summaries

Read the full file on GitHub · 252 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 4d ago First seen · 252 lines · 11 tokens per session scan A cf58b0e4dbfc

Subscribe to this mod's changes

mcp-configuration is a cursor rule published in the GitHub repository ekakit/lightfast-mcp (2 stars, last pushed 1y ago), licensed MIT. It adds 11 tokens to every session and 2,054 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.